240 NEWMAN ON THE 



Ray, Swamraerdam, Latreille, Cuvier, and a host of others, we 

 cannot for a moment hesitate in acknowledging that they were 

 men well versed in the science which they professed to teach. 

 As regards divisional characters no recent writers have attempted 

 to undervalue those which these authors proposed. On the 

 contrary, all our systems, however various, have reference to 

 the writings of these great men. If we build systems of our 

 own, we are compelled to use their materials, or rather their 

 writings are the materials with which we build. 



It requires long and close attention to any branch of Natural 

 History, to ascertain what characters are the least liable 

 to change. Those which remain unaltered, or but little altered, 

 while all around them has undergone repeated change, are 

 invaluable. On the contrary, those parts over which generic, 

 specific, and even sexual distinction holds an unlimited power 

 of change, are amusing and instructive as objects of study ; but 

 in the formation of great and important divisions, even colour 

 and size could not be more utterly valueless. 



Though Entomologists, who have attempted a general 

 arrangement of the objects of which their science treats, have 

 taken various views of those differences on which divisions are 

 founded, all appear to admit the truth that system depends 

 on differences, but scarcely two seem agreed as to what differ- 

 ences, or what mode of differences, are of paramount importance. 

 Some prefer for purposes of division the differences observable 

 in the structure of the mouth, some the differences in the 

 structure of the wings, or of those parts whence the wings 

 arise ; others again have insisted that the only true guide is to 

 be found in the differences of metamorphosis ; and a fourth class 

 of systematists have availed themselves of all these differences. 

 These last are certainly in the right. I say this not because 

 their views correspond with my own, but because we have 

 abundant proof that nature will not be bound by any of our 

 arbitrary and rigid laws. We must trace her in all her infi- 

 nitely varied creations ; and, if we would understand her, we 

 must avail ourselves of each. 



With a view to work out the systems dependent on each 

 series of differences, pointed out by the great men to whom I 

 have already referred, I have endeavoured to trace the cha- 

 racters in question through their every change. The result of 

 the inquiry has been published in three chapters of consider- 



